The 3VA2440-6HK42-0AA0: The interrupting ratings are the headline here: 242 kA at 240 V, 187 kA at 415 V and 440 V, stepping down to 121 kA at 500 V and 13 kA at 690 V. That 242 kA figure at 240 V means it can safely clear a fault upstream of a large transformer or a high-capacity bus — not every 400 A frame carries that kind of short-circuit muscle. For a panel builder, that's the spec that decides whether you need a current-limiting fuse ahead of it or not. The ETU340 release gives you adjustable N-conductor protection (OFF, 50%, 100%) and a fixed long-time delay of 1500 ms at minimum and maximum settings. No communication module on this variant, so it's a standalone thermal-magnetic replacement with electronic precision — no fieldbus integration, just reliable overcurrent and short-circuit protection in a 4-pole package.
Sizing and thermal derating
Rated continuous current holds at 400 A from 40 °C up through 50 °C ambient — that's a solid thermal margin for most panel environments. At 55 °C it derates to 388 A, at 60 °C to 380 A, at 65 °C to 368 A, and at 70 °C to 352 A. If your panel ambient runs hot (say, adjacent to a drive cabinet or in a non-climate-controlled enclosure), you'll want to size the load side for the derated figure, not the nameplate 400 A. Maximum power loss is 63.3 W at rated current — worth factoring into the enclosure thermal calculation if you're stacking several of these on a bus.
Dimensions and panel fit
The breaker measures 184 mm wide, 248 mm high, and 110 mm deep. That 110 mm depth (4.3 inches) is the projection from the mounting surface — critical when you're laying out a shallow enclosure or retrofitting into an existing panel where the deadfront clearance is tight. Width at 184 mm (7.2 inches) for a 4-pole frame is standard for this class; verify your busbar spacing and phase barriers before committing the drill pattern.
Compliance and approvals
Rated insulation voltage Ui is 800 V, and the front face carries IP40 protection — suitable for general-purpose panel mounting where no washdown or dust ingress is expected. Storage temperature range spans -40 °C to 80 °C; operating range is -40 °C to 70 °C. The part carries a reference code per DIN EN 81346-2 (Q for switching devices), which aligns with standard European panel documentation practices.